I also do inbox 0 the exact same way you do but sometimes it's not enough. For example, if an online retailer sends me promotions I don't care about, I'd like them to be auto-archived for when I actually feel like buying something, but I don't want to miss my purchase confirmations.

Google's new categories help and Inbox sounds promising but I feel like there's too much assumption going on in parsing the emails.

Really, I'd like email addresses to be on the domain level. For example, mail@cool_username.gmail.com and flights@cool_username.gmail.com. Then, give me granular control over how "mail" or "flights" get categorized and give me nested categories.